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POSTOPERATIVE sudden death
is a dramatic event occurring in 1.1 per 1,000 anesthetic procedures. 1 A discrepancy between the clinical impression regarding the cause of death and the anatomic findings at autopsy were found in 23–39% of cases studied. 2 In some cases, unsuspected preexisting disease contributing directly to death could be only found at autopsy. Arrhythmogenic right ventricular dysplasia
(ARVD) is a rarely diagnosed autosomal dominant disease described by Fontaine et al.3 in 1979. It mainly occurs in otherwise healthy adolescents and young adults with complex ventricular arrhythmia and effort-related sudden deaths. 3 Only one case of ventricular tachycardia related to ARVD has been described after general anesthesia. 4 We report the cases of two adolescents who had previously undergone multiple anesthetic procedures and died after anesthesia for major orthopedic surgery. In these cases, the diagnosis of ARVD was only made at autopsy.

Case Report

These two cases were observed during a 5-yr period in Hopital Necker-Enfants Malades of Paris, France, which performed 50–60 complex vertebral fusions each year. The two patients were classified as American Society of Anesthesiologists III and were adolescents with a previous history of severe myelomeningocele and Chiari II malformation. Severe muscular scoliosis developed, and anterior thoracic vertebral fusion was required. Both patients had undergone multiple previous neurosurgical, orthopedic, and urological procedures without noticeable complications. Their preoperative cardiac examinations were unremarkable, and electrocardiographic data were considered to be normal. However, in retrospect, the electrocardiogram in the second case depicted T-wave inversion in V1–V2precordial leads. Induction of anesthesia with thiopental, sufentanil, and vecuronium and maintenance with 1 minimum alveolar concentration (MAC) isoflurane and continuous infusion of sufentanil were uneventful. The procedures lasted 9 h. Total blood loss was estimated at 1,300–1,700 ml and was replaced by total perioperative autotransfusion. Final hematocrits were 29 and 28%. After the procedure, the patients regained consciousness rapidly and were transferred to the postoperative intensive care unit, where assisted ventilation was maintained for the first postoperative hours.

Case 1

A 13-yr-old, 44-kg girl underwent tracheal extubation without difficulties 12 h after the end of the orthopedic procedure. The patient was then discharged to the surgical ward, alert and pain-free. Thirty hours after the end of the surgical procedure, she experienced, without preceding symptoms or increased blood loss through surgical drainage, abrupt hypotension (arterial blood pressure, 70/40 mmHg) that did not respond to immediate vascular loading. Continuous electrocardiographic monitoring at this time showed what was considered to be a sinusal tachycardia (heart rate, 140 beats/min). Within minutes, cardiac arrest with asystole occurred without preceding recognized arrhythmia. Despite immediate resuscitation initiated with external chest compression, endotracheal intubation, multiple attempts to cardioversion, and epinephrine and lidocaine infusion, the patient did not regain spontaneous cardiac activity and was pronounced dead 2 h later.

Case 2

While still undergoing mechanical ventilation in the postoperative intensive care unit 4 h after discharge from the operating room, a 16-yr-old, 50-kg girl experienced abrupt hypotension (arterial blood pressure, 65/35 mmHg) with tachycardia that was considered to be sinusal with sporadic polymorphic premature ventricular beats (heart rate, 160 beats/min). Shortly thereafter, monomorphic ventricular tachycardia occurred, followed by a short-lasting episode of ventricular fibrillation and resulting asystole. Despite classic resuscitation that was initiated immediately, she did not regained spontaneous cardiac activity, and resuscitation was discontinued after 2 h.

In both cases, pathologic examination of the heart at autopsy depicted typical features of ARVD with massive replacement of myocytes of the right myocardium by fibroadipose tissue predominating in the mediomural layers. In some places, endocardium was reduced to a thin rim of myocardial tissue. These features of ARVD were associated with a myocardial infiltration with lymphocytes and plasmocytes, suggesting an acute inflammatory reaction associated with chronic degenerative pathology.

Discussion

Sporadic cases of ARVD have been described in young adults and children with no clinically apparent cardiac disorders who experienced exercise-induced sudden deaths and complex ventricular arrhythmias. 4,6–8 Typical histologic findings are nonhomogenous replacement of more than 20% of the myocytes by a fibroadipose tissue predominantly in the subepicardial and myocardial layers. 9 The hereditary autosomal dominant transmission of ARVD has been related to the localization of genes on chromosome 14q23-q24 and a locus at chromosome 3p23 with variable expression and incomplete penetrance. 10,11 Its prevalence is estimated to be approximately 1 in 5,000, with a 50% penetrance in some families. Recessive forms with more severe expression, as in the Naxos disease, in which dysplasia is associated with palmoplantar keratosis, have been described. 4 The risk of sudden death has been estimated to be 2.5% per year. 11 Severity of ventricular dysplasia does not correlate with long-term outcome or arrhythmic events, but the risk of sudden death seems to be higher in patients without previous episodes of ventricular tachycardia (VT), in those who have dilated right ventricle, and in those who have experienced syncope.

The implications of ARVD for anesthetists are important because patients with ARVD are particularly at risk for development of VT or sudden death in the perioperative period. There are no previously described cases of the association between myelomeningocele and sudden postoperative death, and there is only one previously described case of ARVD causing abrupt ventricular arrhythmia during general anesthesia. 5 These two consecutive cases are probably coincidental, and family genetic screening results were negative. Interestingly, both these patients had multiple previous procedures without complications. These severely disabled children probably had progressing ARVD but remained asymptomatic. The mechanism of sudden death could be exercise-induced stress related to a major surgical procedure resulting in abrupt tachyarrhythmia. In retrospect, hypotension, which was the first reported symptom, probably resulted from an episode of tachyarrhythmia that was falsely interpreted as sinusal tachycardia. Histologic findings suggested some form of associated acute myocarditis of unknown origin that could play a secondary role in the abrupt development of tachyarrhythmia. A careful and oriented cardiac evaluation is mandatory in patients with personal or familial history of sudden death or VT in young individuals, exercise-induced palpitations, or syncope. Symptoms are induced by exercise, and physical examination results are normal at rest in 50% of the patients. 4 Giant waves observed by jugular inspection, murmur, or tricuspid regurgitation related to dilated right cavities are only observed in older patients with diffuse myocardial involvement. Common electrocardiographic anomalies include T-wave inversion in anterior precordial leads, ventricular premature complexes, and monomorphic VT with left bundle branch block induced by exercise. Surface electrocardiography shows longer QRS duration and late potential duration over the dysplastic areas. Young patients presenting with T-wave inversion on anterior precordial leads should have echocardiography that is suggestive of severe ARVD with major dilatation when apical dyskinesia, right ventricular dilatation, structural abnormality, diastolic bulge, or systolic dyskinesia of the infero-basal wall are noted. 4 When present, these anomalies should lead to noninvasive explorations with spiral computed tomography and magnetic resonance imaging to define morphology of the right cavities and to identify early stages, extent of the disease, and the site of the dominant fatty cardiac involvement with spin echo magnetic resonance imaging. 12 This should be completed by ventricular angiography, which is the gold standard for clinical diagnosis. 9 The key to histologic diagnosis is endocardial biopsy. More than 90% of asymptomatic patients with high clinical risks and positive echocardiography have positive myocardial biopsy and are at risk for experiencing serious ventricular arrhythmia and sudden death. However, in some cases, the patchy nature of the myocardial infiltration makes endocardial biopsy an unreliable diagnostic technique. Patients at high risk should benefit from treatment before scheduled surgical procedures. Pharmacologic treatment is aimed at controlling emergence or recurrence of VT, but the suppression of VT has not shown a direct survival benefit. 4 The most useful antiarrhythmic drug is sotalol, which prevents severe arrhythmia in 60–70% of patients. 13 In patients with drug refractoriness, endocardial fulguration and encircling ventriculotomy have been proposed. 14 The progress in technology of implantable cardioverter defibrillators with nonthoracotomy leads has made this technique the most safe and efficient for preventing VT. 15 During anesthesia and recovery, special attention should be made to avoid noxious stimuli during light anesthesia, uncompensated blood losses, hypercarbia, hypoxia, and acidosis capable of inducing cardiac arrhythmia. 16 Halothane should not be used. Finally, unexplained perioperative sudden death in young patients should command autopsy with careful cardiac examination for possible fatty cardiac involvement featuring ARVD. 2 Familial screening is necessary when ARVD has been diagnosed.